Telephony over packet networks, particularly over wide area networks such as the Internet, has received considerable attention in recent years. Specifically, scientists have begun exploring the possibility of sending voice and video information streams over packet switched data networks. The transmission of such information streams over packet switched networks can be more cost efficient than traditional telephony, which requires a dedicated circuit between the calling and called party. Transmitting voice information on the data network also removes the requirement to have a separate voice/telephony network.
Computer telephone integration has been widely applied to traditional telephony methods and apparatus, but has not as yet been successfully applied to the methods and apparatus used for packet network telephony. This invention specifies novel apparatus and methods, supplementary to known packet network telephony apparatus and methods, which enable CTI capabilities in such an environment, and use them to process telephone calls. In particular, the invention described herein enables packet network control by a third party which is deemed to be preferred to first party control systems.
One possible set of methods and apparatus for completing calls over a packet switched network, which calls can handle voice and other information streams, is defined by ITU Recommendation H.323. The H.323 standard is available from the International Telecommunication Union, of Geneva, Switzerland, and is hereby incorporated herein by this reference. The H.323 standard defines various protocols dealing with call control, call setup, call termination, and other similar techniques known to those in the packet network telephony art.
The H.323 standard defines a functional entity called a gatekeeper. The gatekeeper handles network functions such as bandwidth control, zone management, address translation, and admissions control for a designated set of network terminals. While all these functions are further defined in the previously incorporated standard, we set forth two examples below.
Bandwidth control provides a protocol by which the gatekeeper allocates a particular amount of network bandwidth to a particular connection. The gatekeeper can be contacted by either the calling or called party in order to change the amount of bandwidth allocated to a particular call, for example, because one endpoint only has access to a limited set of voice codes.
As another example, the gatekeeper performs zone management. This function, as further defined in the H.323 standard, provides a mechanism for allocating sets of different terminals and other nodes in the network to a particular gatekeeper. The H.323 standard provides a mechanism for dynamically altering the allocation of different network nodes to different gatekeepers.
The gatekeeper function provides services analogous to the call processing function within a private branch exchange (PBX) in conventional telephony. In traditional telephony, CTI features are provided by creating an interface between external application software and the call processing function within the PBX. By contrast, in the known packet network telephony art, interfaces to the gatekeeper are only defined from other gatekeepers, end points, and other network entities.
Utilizing and building upon the call processing functions of an H.323 gatekeeper, or an analogous entity defined by other packet switched data network standard, call processing applications commonly known in conventional telephony can be implemented in a packet switched data network. The present invention describes the implementation, over a packet switched data network, a system for the storage and retrieval of a variety of communications messages of various types. In such a system a user can manage her voice mail, email, pager, fax and data communications under a “one-stop shopping” universal messaging system, reaping the benefits of telephony based communications integrated within packet data networks. Such functionalities are commonly known in conventional telephony as “Universal Messaging”, “Universal Queuing”, and the like.